Abstract: A novel extractant mixture, di-2-ethylhexyl phosphate (DEHPA) plus HX, was proposed and
tested for recovering gallium from sulfate solution. It was found that the extraction
capacity of DEPHA for gallium from sulfate solution could be enhanced significantly due to
the synergistic effect of acidic extractant HX. Gallium extraction is negligible below pH 0
and highly sensitive to pH of aqueous phase in the range from 0 to 1, and satisfactory
extraction can be gained at pH＞1. More than 96% Ga extraction was obtained using 15% DEHPA
plus 2% HX. Although Fe (Ⅲ) was found to be extracted preferentially to Ga (Ⅲ), effective
extraction of Ga (Ⅲ) was possible by reducing ferric to the ferrous state prior to
extraction. A loaded organic phase containing 0.48g. L-1 Ga could be produced from solution
of 0.12g@L-1 Ga at A/O ratio of 4: 1 via three mixer-settler operation stages.Gallium was
stripped quantitatively from the loaded organic phase with 1.5 mol@L-1 of sulfuric acid.

Key words: gallium, synergistic extraction, DEHPA, sulfate solution

摘要： A novel extractant mixture, di-2-ethylhexyl phosphate (DEHPA) plus HX, was proposed and
tested for recovering gallium from sulfate solution. It was found that the extraction
capacity of DEPHA for gallium from sulfate solution could be enhanced significantly due to
the synergistic effect of acidic extractant HX. Gallium extraction is negligible below pH 0
and highly sensitive to pH of aqueous phase in the range from 0 to 1, and satisfactory
extraction can be gained at pH＞1. More than 96% Ga extraction was obtained using 15% DEHPA
plus 2% HX. Although Fe (Ⅲ) was found to be extracted preferentially to Ga (Ⅲ), effective
extraction of Ga (Ⅲ) was possible by reducing ferric to the ferrous state prior to
extraction. A loaded organic phase containing 0.48g. L-1 Ga could be produced from solution
of 0.12g@L-1 Ga at A/O ratio of 4: 1 via three mixer-settler operation stages.Gallium was
stripped quantitatively from the loaded organic phase with 1.5 mol@L-1 of sulfuric acid.

关键词: gallium;synergistic extraction;DEHPA;sulfate solution